diff --git a/meson.build b/meson.build
index 9d0f71a..8fa7cf9 100644
--- a/meson.build
+++ b/meson.build
@@ -51,6 +51,7 @@ executable(
     'src/vm.c',
 
     'src/symtable.c',
+    'src/fun.c',
   ],
   dependencies: [
     m_dep
diff --git a/src/compiler.c b/src/compiler.c
index 9fa5ac0..0bb3b6c 100644
--- a/src/compiler.c
+++ b/src/compiler.c
@@ -341,9 +341,139 @@ void compile_node(compiler* self, node* root, program* prog)
 			compile_number(self, root, prog, OP_IADD, OP_FADD);
 		}
 	}
+	else if (root->type == NODE_FUN)
+	{
+		// init body
+		compiler comp;
+		compiler_init(&comp);
+		program* fun_prog = malloc(sizeof(program));
+		program_init(fun_prog);
+		node* block = root->children.data[root->children.size - 1];
+		
+		// add params
+		for (size_t i=0; i<root->children.size; i++)
+		{
+			node* param = root->children.data[i];
+
+			if (param->type == NODE_FUN_PARAM)
+			{
+				char const* param_name = param->children.data[0]->value;
+				type* param_ty = 
+					type_new_from_node(param->children.data[1]);
+
+				symtable_declare(comp.sym, param_name
+						, param_ty
+						, param->children.data[0]);
+
+				type_free(param_ty); free(param_ty);
+			}
+		}
+		
+
+		// compile body
+		compile_node(&comp, block, fun_prog);
+		compiler_free(&comp);
+
+		// init fun object
+		cstatic cs;
+		cstatic_init(&cs);
+		
+		fun* fn = malloc(sizeof(fun));
+		type* ty = cstatic_resolve_new(&cs, self->sym, root);
+
+		fun_init(fn, ty, (struct program*) fun_prog);
+		program_free(fun_prog); free(fun_prog); fun_prog = NULL;
+
+		type_free(ty); free(ty);
+		
+		// create value
+		value* val = malloc(sizeof(value));
+		value_init_fun(val, fn, root->lineno);
+		
+		// push it
+		program_add_instr(
+			prog,
+			OP_PUSH,
+			program_add_pool(prog, val)
+		);
+
+		value_free(val); free(val);
+		fun_free(fn); free(fn);
+
+		cstatic_free(&cs);
+	}
+	else if (root->type == NODE_CALL)
+	{
+		//{char c[512]; node_str(root, c, 512); printf("%s\n", c);}
+		char const* fun_name = root->children.data[0]->value;
+		node* args = root->children.data[1];
+		
+		symentry* entry = symtable_find(self->sym, fun_name);
+		assert(entry);
+		
+		program_add_instr(prog, OP_LOAD, entry->id);
+
+		for (size_t i=0; i<args->children.size; i++)
+		{
+			node* arg = args->children.data[i];
+			compile_node(self, arg, prog);
+		}
+
+		program_add_instr(prog, OP_CALL, args->children.size);
+	}
+	else if (root->type == NODE_RETURN)
+	{
+		compile_children(self, root, prog);
+		program_add_instr(prog, OP_RET, NO_PARAM);
+	}
+	else if (root->type == NODE_FUN_TYPE)
+	{
+		type* ty = malloc(sizeof(type));
+		type_init(ty, TY_FUNCTION);
+
+		node* lhs = root->children.data[0];
+		
+		size_t lhs_sz = lhs->children.size;
+
+		for (size_t i=0; i<lhs_sz; i++)
+		{
+			type* sub = type_new_from_node(
+					lhs->children.data[lhs_sz - 1 - i]);
+			type_add_sub_type(ty, sub);
+			type_free(sub); free(sub);
+		}
+		
+		if (root->children.data[1]->children.size > 0)
+		{
+			node* rhs = root->children.data[1];
+			size_t rhs_sz = rhs->children.size;
+			for (size_t i=0; i<rhs_sz; i++)
+			{
+				type* sub = type_new_from_node( 
+						rhs->children.data[rhs_sz - 1 - i]);
+				sub->kind = KIND_RETURN;
+				type_add_sub_type(ty, sub);
+				type_free(sub); free(sub);
+			}
+		}
+
+		value val;
+		value_init_type(&val, 
+				ty,
+				root->lineno);
+		
+		size_t idx = program_add_pool(prog, &val);
+		program_add_instr(prog, OP_PUSH, idx);
+		
+
+		type_free(ty);
+		free(ty);
+
+		value_free(&val);
+	}
 	else if (root->type == NODE_TYPE)
 	{
-		type* ty = compile_get_type(self, root);
+		type* ty = type_new_from_node(root);
 				
 		value val;
 		value_init_type(&val, 
@@ -572,71 +702,6 @@ void compile_children(compiler* self, node* root, program* prog)
 	}
 }
 
-type* compile_get_type(compiler* self, node* root)
-{
-	assert(self);
-	assert(root);
-	type* ty = malloc(sizeof(type));
-
-	if (strcmp(root->value, "int") == 0)
-	{
-		type_init(ty, TY_INTEGER);
-	}
-
-	else if (strcmp(root->value, "float") == 0)
-	{
-		type_init(ty, TY_FLOAT);
-	}
-
-	else if (strcmp(root->value, "str") == 0)
-	{
-		type_init(ty, TY_STRING);
-	}
-
-	else if (strcmp(root->value, "bool") == 0)
-	{
-		type_init(ty, TY_BOOLEAN);
-	}
-
-	else if (strcmp(root->value, "type") == 0)
-	{
-		type_init(ty, TY_TYPE);
-	}
-
-	else if (strcmp(root->value, "array") == 0)
-	{
-		type_init(ty, TY_ARRAY);
-		ty->kind = KIND_SEQUENTIAL;
-	}
-	else if (root->type == NODE_ADD)
-	{
-		type_init(ty, TY_TYPE);
-		ty->kind = KIND_DISJUNCTION;
-	}
-	else if (root->type == NODE_MUL)
-	{
-		type_init(ty, TY_TYPE);
-		ty->kind = KIND_CONJUNCTION;
-	}
-	else
-	{
-		fprintf(stderr, 
-			"E(%d): cannot compile unknown type '%s'.\n",
-			root->lineno,
-			NodeTypeStr[root->type]);
-	}
-
-	for (size_t i=0; i<root->children.size; i++)
-	{
-		type* sub = compile_get_type(self, root->children.data[i]);
-		type_add_sub_type(ty, sub);
-		type_free(sub);
-		free(sub);
-	}
-
-	return ty;
-}
-
 void compile_if(compiler* self, node* root, program* prog)
 {
 	if (root->children.size == 1)
diff --git a/src/compiler.h b/src/compiler.h
index b6d6227..386625e 100644
--- a/src/compiler.h
+++ b/src/compiler.h
@@ -30,8 +30,6 @@ void compiler_pop_info(compiler* self);
 void compile_node(compiler* self, node* root, program* prog);
 void compile_children(compiler* self, node* root, program* prog);
 
-type* compile_get_type(compiler* self, node* root);
-
 void compile_number(compiler* self, node* root, program* prog, 
 		int integer_op,
 		int float_op);
diff --git a/src/cstatic.c b/src/cstatic.c
index db476e9..1152089 100644
--- a/src/cstatic.c
+++ b/src/cstatic.c
@@ -4,11 +4,26 @@
 void cstatic_init(cstatic* self)
 {
 	assert(self);
+
+	self->fun_types.size = 0;
+	self->fun_types.capacity = 1;
+	self->fun_types.data = malloc(sizeof(type*) * self->fun_types.capacity);
 }
 
 void cstatic_free(cstatic* self)
 {
 	assert(self);
+
+	for (size_t i=0; i<self->fun_types.size; i++)
+	{
+		type_free(self->fun_types.data[i]);
+		free(self->fun_types.data[i]);
+	}
+
+	free(self->fun_types.data);
+	self->fun_types.size = 0;
+	self->fun_types.capacity = 0;
+	self->fun_types.data = NULL;
 }
 
 type* cstatic_new_type(cstatic* self, int base_type)
@@ -35,10 +50,96 @@ type* cstatic_resolve_new(cstatic* self, symtable* sym, node* ast)
 	assert(self);
 	assert(ast);
 	
+	if (ast->type == NODE_FUN)
+	{
+		type* ty = cstatic_new_type(self, TY_FUNCTION);
+
+		size_t i = 0;
+
+		while (i < ast->children.size
+			&& ast->children.data[i]->type == NODE_FUN_PARAM)
+		{
+			type* param_ty = 
+				type_new_from_node(
+				ast->children.data[i]->children.data[1]
+			);
+
+			type_add_sub_type(ty, param_ty);
+			type_free(param_ty); free(param_ty);
+
+			i++;
+		}
+
+		if (i < ast->children.size 
+				&& ast->children.data[i]->type == NODE_FUN_RET)
+		{
+			node* ret = ast->children.data[i];
+
+			for (size_t i=0; i<ret->children.size; i++)
+			{
+				type* r = type_new_from_node(ret->children.data[i]);
+				r->kind = KIND_RETURN;
+				type_add_sub_type(ty, r);
+				type_free(r); free(r);
+			}
+		}
+
+		return ty;
+	}
+
+	if (ast->type == NODE_CALL)
+	{
+		char const* fun_name = ast->children.data[0]->value;
+		
+		symentry* entry = symtable_find(sym, fun_name);
+		assert(entry);
+		
+		type* fun_type = entry->ty;
+		assert(fun_type);
+
+		size_t ret_count = fun_type->sub_types.size;
+		
+		if (ret_count > 0)
+		{
+			type* ret_type = fun_type->sub_types.data[ret_count - 1];
+			assert(ret_type);
+			
+			if (ret_type->kind == KIND_RETURN)
+			{
+				type* res = type_new_clone(ret_type);
+				res->kind = KIND_CONJUNCTION;
+				return res;
+			}
+		}
+
+		return NULL;
+	}
+
+	if (ast->type == NODE_RETURN)
+	{
+		return cstatic_resolve_new(self, sym, ast->children.data[0]);
+	}
+
+	if (ast->type == NODE_IF)
+	{
+		type* ty = cstatic_resolve_new(self, 
+				sym,
+				ast->children.data[1]);
+		return ty;
+	}
+
+	if (ast->type == NODE_DO)
+	{
+		type* ty = cstatic_resolve_new(self, 
+				sym,
+				ast->children.data[0]);
+		return ty;
+	}
 	if (ast->type == NODE_IDENT)
 	{
 		symentry* entry = symtable_find(sym,
 				ast->value);
+		assert(entry);
 		type* ty = type_new_clone(entry->ty);
 		return ty;
 	}
@@ -184,7 +285,8 @@ type* cstatic_resolve_new(cstatic* self, symtable* sym, node* ast)
 		return cstatic_new_type(self, TY_STRING);
 	}
 
-	else if (ast->type == NODE_TYPE)
+	else if (ast->type == NODE_TYPE
+		|| ast->type == NODE_FUN_TYPE)
 	{
 		return cstatic_new_type(self, TY_TYPE);
 	}
@@ -250,7 +352,7 @@ int cstatic_check(cstatic* self, node* ast, symtable* sym, char* msg, size_t siz
 
 			if (!status)
 			{
-				return -1;
+				return 0;
 			}
 		}
 
@@ -259,6 +361,157 @@ int cstatic_check(cstatic* self, node* ast, symtable* sym, char* msg, size_t siz
 		return 1;
 	}
 
+	// Function Stuff
+	if (ast->type == NODE_FUN)
+	{
+		type* ty = cstatic_resolve_new(self, sym, ast);
+		
+		cstatic_push_fun(self, ty);
+		
+		type_free(ty); free(ty);	
+
+		symtable* inner_table = symtable_new_clone(sym);
+		
+		// function args
+		for (size_t i=0; i<ast->children.size; i++)
+		{
+			node* child = ast->children.data[i];
+
+			if (child->type == NODE_FUN_PARAM)
+			{
+				char const* name = child->children.data[0]->value;
+				type* t = type_new_from_node(child->children.data[1]); 
+
+				symtable_declare_mut(inner_table, name, t, child);
+
+				type_free(t); free(t);
+			}
+		}
+
+		int status = cstatic_check(self, 
+					ast->children.data[ast->children.size - 1],
+					inner_table, 
+					msg,
+					size
+					);
+
+		symtable_free(inner_table); free(inner_table);
+		cstatic_pop_fun(self);
+		
+
+		return status;
+	}
+
+	// Function Stuff
+	if (ast->type == NODE_RETURN)
+	{
+		type* ret_ty = cstatic_resolve_new(self, sym, ast);
+		type* fun_ty = cstatic_top_fun(self);
+		
+		type* fun_res = NULL;
+		
+		for (size_t i=0; i<fun_ty->sub_types.size; i++)
+		{
+			if (fun_ty->sub_types.data[i]->kind == KIND_RETURN)
+			{
+				fun_res = type_new_clone(fun_ty->sub_types.data[i]);
+				fun_res->kind = KIND_CONJUNCTION;	
+				break;
+			}
+		}
+		
+		assert(fun_res);
+
+		int status = cstatic_check_same_type_ptr(
+			self,
+			ast,
+			fun_res,
+			ret_ty,
+			sym,
+			msg,
+			size
+		);
+		
+		if (status)
+		{
+			if (fun_res)
+			{
+				type_free(fun_res); free(fun_res);
+			}
+
+			type_free(ret_ty); free(ret_ty);
+		}
+
+		return status;
+	}
+
+	if (ast->type == NODE_CALL)
+	{
+		char const* fun_name = ast->children.data[0]->value;
+		symentry* entry = symtable_find(sym, fun_name);
+		assert(entry);
+		
+		type* fun_type = entry->ty;
+		
+		node* args = ast->children.data[1];
+		size_t arity = 0;
+		
+		for (size_t i=0; i<fun_type->sub_types.size; i++)
+		{
+			type* ty = fun_type->sub_types.data[i];
+			if (ty->kind != KIND_RETURN)
+			{
+				arity++;
+			}
+		}
+
+		if (arity != args->children.size)
+		{
+			snprintf(msg, size, "E(%d): function arity mismatch: "
+					"expected '%ld', got '%ld'.\n",
+					args->lineno,
+					arity,
+					args->children.size
+					);
+			return 0;
+		}
+
+		for (size_t i=0; i<args->children.size; i++)
+		{
+
+			type* sub = type_new_clone(fun_type->sub_types.data[i]);
+			assert(sub);
+
+			type* arg_type = cstatic_resolve_new(
+				self,
+				sym,
+				args->children.data[i]
+			);
+
+			int status = cstatic_check_same_type_ptr(
+				self,
+				args->children.data[i],
+				sub,
+				arg_type,
+				sym,
+				msg,
+				size
+			);
+			
+			if (!status)
+			{
+				return 0;
+			}
+
+			type_free(sub); free(sub);
+			type_free(arg_type); free(arg_type);
+
+		}
+
+
+		return 1;
+	}
+
 	// Children
 	for (size_t i=0; i<ast->children.size; i++)
 	{
@@ -914,3 +1167,38 @@ int cstatic_check_same_type(cstatic* self, node* lhs, node* rhs, symtable* sym,
 
 	return 1;
 }
+
+void cstatic_push_fun(cstatic* self, type* fun_ty)
+{
+	assert(self);
+	assert(fun_ty);
+
+	if (self->fun_types.size >= self->fun_types.capacity)
+	{
+		self->fun_types.capacity *= 2;
+		self->fun_types.data = realloc(
+			self->fun_types.data,
+			sizeof(type*) * self->fun_types.capacity
+		);
+	}
+
+	self->fun_types.data[self->fun_types.size] = type_new_clone(fun_ty);
+	self->fun_types.size++;	
+
+}
+
+void cstatic_pop_fun(cstatic* self)
+{
+	assert(self->fun_types.size > 0);
+	
+	type_free(self->fun_types.data[self->fun_types.size - 1]);
+	free(self->fun_types.data[self->fun_types.size - 1]);
+
+	self->fun_types.size--;
+}
+
+type* cstatic_top_fun(cstatic* self)
+{
+	assert(self->fun_types.size > 0);
+	return self->fun_types.data[self->fun_types.size - 1];
+}
diff --git a/src/cstatic.h b/src/cstatic.h
index 9b6d3ad..e805ea9 100644
--- a/src/cstatic.h
+++ b/src/cstatic.h
@@ -8,7 +8,11 @@
 #define TYPE_END (-1)
 
 typedef struct {
-	int _unused;
+	struct {
+		size_t size;
+		size_t capacity;
+		type** data;
+	} fun_types;
 } cstatic;
 
 void cstatic_init(cstatic* self);
@@ -33,4 +37,7 @@ int cstatic_check_same_type_ptr(cstatic* self,
 int cstatic_check_same_type(cstatic* self, node* lhs, node* rhs, symtable* sym,
 		char* msg, size_t size);
 
+void cstatic_push_fun(cstatic* self, type* fun_ty);
+void cstatic_pop_fun(cstatic* self);
+type* cstatic_top_fun(cstatic* self);
 #endif
diff --git a/src/fun.c b/src/fun.c
new file mode 100644
index 0000000..6dbfa32
--- /dev/null
+++ b/src/fun.c
@@ -0,0 +1,46 @@
+#include "fun.h"
+#include "program.h"
+
+void fun_init(fun* self, type* ty, struct program* prog)
+{
+	assert(self);
+	self->ty = type_new_clone(ty);
+	self->prog = program_new_clone(prog);
+}
+
+void fun_free(fun* self)
+{
+	assert(self);
+	type_free(self->ty); free(self->ty);
+
+	program_free(self->prog);
+	free(self->prog);
+	self->prog = NULL;
+}
+
+fun* fun_new_clone(fun* self)
+{
+	assert(self);
+	fun* clone = malloc(sizeof(fun));
+	fun_init(clone, self->ty, self->prog);
+
+	return clone;
+}
+
+size_t fun_str(fun* self, char* buffer, size_t size)
+{
+	assert(self);
+	assert(buffer);
+	size_t sz = 0;
+
+	sz += snprintf(buffer + sz, size - sz, "function");
+
+	return sz;
+}
+
+int fun_equals(fun* self, fun* lhs)
+{
+	assert(self);
+	assert(lhs);
+	return 0; // TODO to impl
+}
diff --git a/src/fun.h b/src/fun.h
new file mode 100644
index 0000000..90a57fe
--- /dev/null
+++ b/src/fun.h
@@ -0,0 +1,21 @@
+#ifndef FUN_H
+#define FUN_H
+
+#include "commons.h"
+#include "type.h"
+
+struct program;
+
+typedef struct {
+	type* ty;
+	struct program* prog;
+} fun;
+
+void fun_init(fun* self, type* ty, struct program* prog);
+void fun_free(fun* self);
+
+fun* fun_new_clone(fun* self);
+size_t fun_str(fun* self, char* buffer, size_t size);
+int fun_equals(fun* self, fun* lhs);
+
+#endif
diff --git a/src/lex.l b/src/lex.l
index 4e1e2fa..1fdd7cf 100644
--- a/src/lex.l
+++ b/src/lex.l
@@ -1,4 +1,5 @@
 %{
+
 	#include "parser.h"
 	#include "src/utils.h"
 	int line = 1;
@@ -14,10 +15,12 @@ INTEGER -?[0-9]+
 FLOAT -?[0-9]+\.[0-9]+
 STRING \"[^"]*\"
 TYPE (int|float|bool|str|array|type)
-IDENT [_A-Za-z][_A-Za-z0-9]* 
+IDENT [_A-Za-z][_A-Za-z0-9]*  
+SEP [\n]|[;]
 
 %%
 {COMMENT} {}
+{SEP} { line++; return SEP; }
 "\n" { line++; }
 {WHITESPACES} {}
 
@@ -26,6 +29,9 @@ IDENT [_A-Za-z][_A-Za-z0-9]*
 	return TYPE;
 }
 
+"fun" { return FUN; }
+"as" { return AS; }
+"return" { return RETURN; }
 "while" { return WHILE; }
 "break" { return BREAK; }
 "continue" { return CONTINUE; }
@@ -42,6 +48,7 @@ IDENT [_A-Za-z][_A-Za-z0-9]*
 "<" { return LT; }
 ">" { return GT; }
 "," { return COMMA; }
+":" { return COLON; }
 "+" { return ADD; }
 "-" { return SUB; }
 "*" { return MUL; }
diff --git a/src/main.c b/src/main.c
index 482f279..f9ae9c9 100644
--- a/src/main.c
+++ b/src/main.c
@@ -5,6 +5,7 @@
 #include "vm.h"
 #include "cstatic.h"
 
+
 extern FILE* yyin;
 extern node* ast;
 extern void stack_push(node*);
@@ -13,6 +14,8 @@ extern void stack_free();
 
 int main(int argc, char** argv)
 {
+	int DEBUG = argc > 2;
+
 	if (argc > 1) 
 	{
 		yyin = fopen(argv[1], "r");
@@ -27,6 +30,16 @@ int main(int argc, char** argv)
 	ast = stack_pop();
 	stack_free();
 	
+
+	if (DEBUG)
+	{
+		size_t const BUF = 1024;
+		char buffer[BUF];
+		memset(buffer, 0, BUF);	
+		node_str(ast, buffer, BUF);
+		printf("-- ast ---\n%s\n\n", buffer);
+	}
+
 	// Static checking
 	symtable sym;
 	symtable_init(&sym);
@@ -52,24 +65,25 @@ int main(int argc, char** argv)
 
 	compile_node(&comp, ast, &prog);	
 	
+	if (DEBUG)
+	{
+		size_t const BUF = 1024;
+		char buffer[BUF];
+		memset(buffer, 0, BUF);	
+		program_str(&prog, buffer, BUF);
+		printf("--- program ---\n%s\n", buffer);
+	}
+
 	// Execution
 	vm v;
 	vm_init(&v);
 
 	vm_exec(&v, &prog);
 
-	if (0) // DEBUG
+	if (DEBUG)
 	{
 		size_t const BUF = 1024;
 		char buffer[BUF];
-		memset(buffer, 0, BUF);	
-		node_str(ast, buffer, BUF);
-		printf("-- ast ---\n%s\n\n", buffer);
-	
-		memset(buffer, 0, BUF);	
-		program_str(&prog, buffer, BUF);
-		printf("--- program ---\n%s\n", buffer);
-
 		memset(buffer, 0, BUF);	
 		vm_str(&v, buffer, BUF);
 		printf("--- stack ---\n%s\n", buffer);
diff --git a/src/node.h b/src/node.h
index 9ebf9de..b04084b 100644
--- a/src/node.h
+++ b/src/node.h
@@ -14,7 +14,9 @@
 	G(NODE_GT), G(NODE_GE), G(NODE_VARDECL), G(NODE_IDENT), \
 	G(NODE_CONSTDECL), G(NODE_ASSIGN), G(NODE_DO), G(NODE_IS), \
 	G(NODE_IF), G(NODE_ELSE), G(NODE_BLOCK), \
-	G(NODE_WHILE), G(NODE_CONTINUE), G(NODE_BREAK)
+	G(NODE_WHILE), G(NODE_CONTINUE), G(NODE_BREAK), \
+	G(NODE_COLON), G(NODE_FUN_TYPE), G(NODE_RETURN), G(NODE_FUN), \
+	G(NODE_FUN_PARAM), G(NODE_FUN_RET), G(NODE_CALL), G(NODE_ARGS)
 
 
 #include "mutils.h"
diff --git a/src/opcodes.h b/src/opcodes.h
index cf985f0..95c28e7 100644
--- a/src/opcodes.h
+++ b/src/opcodes.h
@@ -47,7 +47,9 @@
 	G(OP_ASTORE), \
 	G(OP_TEQ), \
 	G(OP_BRF), \
-	G(OP_BR)
+	G(OP_BR), \
+	G(OP_CALL), \
+	G(OP_RET)
 
 
 enum Opcodes {
diff --git a/src/parser.y b/src/parser.y
index 52e962a..6fe396e 100644
--- a/src/parser.y
+++ b/src/parser.y
@@ -2,7 +2,6 @@
 	#include <stdio.h>
 	#include <stdlib.h>
 	#include "src/node.h"
-
 	extern int line;
 	void yyerror(char const*);
 	node* ast = NULL;
@@ -16,11 +15,13 @@
 	void stack_free();
 %}
 
+%define parse.error verbose
+
 %union {
 	char* str;
 	size_t n_children;
 };
-
+%token SEP
 %token IF_COND
 %token ELSE_COND
 %token WHILE
@@ -29,7 +30,9 @@
 %left ASSERT
 %token <str> TYPE BOOLEAN INTEGER FLOAT STRING IDENT
 %type <n_children> expr exprs prog array builtins
-%type <n_children> expr_list type type_list ident if 
+%type <n_children> expr_list type type_list ident if
+%type <n_children> fun_rets fun_params fun_param fun 
+%type <n_children> fun_ret_list fun_call fun_args any instr
 %left EQ NE
 %left LT GT LE GE
 %left AND
@@ -39,11 +42,11 @@
 %left POW
 %left NOT
 %token OPAR CPAR 
-%token OSQUARE CSQUARE COMMA
+%token OSQUARE CSQUARE COMMA COLON
 %token LET LET_MUT ASSIGN DO END
 %type <n_children> expr_unop block if_rec
 %left IS
-
+%token RETURN FUN AS
 %%
 
 prog: 
@@ -76,30 +79,19 @@ prog:
     }
 ;
 
-exprs: 
-	exprs expr { $$ = $1 + $2; }
+sep: SEP | sep SEP;
+optsep: | sep;
 
-	| expr { $$ = $1; }
+exprs: 
+	exprs optsep instr sep { $$ = $1 + $3; }
+	| optsep instr sep { $$ = $2; }
 	
 ;
 
+any: expr { $$ = $1; } | instr { $$ = $1; };
 
 expr:
-	CONTINUE {
-		node* n = malloc(sizeof(node));
-		node_init(n, NODE_CONTINUE, "", line);
-		stack_push(n);
-		$$ = 1;
-	}
-
-	| BREAK {
-		node* n = malloc(sizeof(node));
-		node_init(n, NODE_BREAK, "", line);
-		stack_push(n);
-		$$ = 1;
-	}
-
-	| WHILE expr block END {
+	WHILE expr block END {
 		node* n = malloc(sizeof(node));
 		node_init(n, NODE_WHILE, "", line);
 		
@@ -144,24 +136,6 @@ expr:
 		$$ = 1;
 	}
 
-    	// INDEX
-	| expr array ASSIGN expr {
-		node* n = malloc(sizeof(node));
-		node_init(n, NODE_ASSIGN, "", line);
-
-		node* expr_node = stack_pop();
-		node* array_node = stack_pop();
-		node* ident_node = stack_pop();
-
-		node_add_child(n, ident_node);
-		node_add_child(n, array_node);
-		node_add_child(n, expr_node);
-
-		stack_push(n);
-
-		$$ = 1;
-	}
-
     	| expr array {
 		node *n = malloc(sizeof(node));
 		node_init(n, NODE_INDEX, "", line);
@@ -185,51 +159,6 @@ expr:
 	| ident {
 	}
 	
-	| LET_MUT ident ASSIGN expr {
-		node* n = malloc(sizeof(node));
-		node_init(n, NODE_VARDECL, "", line);
-
-		node* rhs = stack_pop();
-		node* lhs = stack_pop();
-
-		node_add_child(n, lhs);
-		node_add_child(n, rhs);
-
-		stack_push(n);
-
-		$$ = 1;
-	}
-
-	| LET ident ASSIGN expr {
-		node* n = malloc(sizeof(node));
-		node_init(n, NODE_CONSTDECL, "", line);
-
-		node* rhs = stack_pop();
-		node* lhs = stack_pop();
-
-		node_add_child(n, lhs);
-		node_add_child(n, rhs);
-
-		stack_push(n);
-
-		$$ = 1;
-	}
-	
-	| ident ASSIGN expr {
-		node* n = malloc(sizeof(node));
-		node_init(n, NODE_ASSIGN, "", line);
-
-		node* rhs = stack_pop();
-		node* lhs = stack_pop();
-
-		node_add_child(n, lhs);
-		node_add_child(n, rhs);
-
-		stack_push(n);
-
-		$$ = 1;
-	}
-
 	// EXPRESSIONS
     	| array {
 		$$ = 1;
@@ -239,16 +168,6 @@ expr:
 		$$ = $1;
 	}
 
-    	| ASSERT expr {
-		node *n = malloc(sizeof(node));
-		node_init(n, NODE_ASSERT, "", line);
-		node_add_child(n, stack_pop());
-		stack_push(n);
-
-		$$ = 1;
-	}
-
-
 	| expr LT expr {
 		node *n = malloc(sizeof(node));
 		node_init(n, NODE_LT, "", line);
@@ -414,11 +333,113 @@ expr:
 	}
 
 	| expr_unop {}
+
+	| fun_call { $$ = $1; } 
 	
 ;
 
+instr:
+	expr 
+
+	| RETURN expr {
+		node* n = malloc(sizeof(node));
+		node_init(n, NODE_RETURN, "", line);
+
+		node_add_child(n, stack_pop());
+		stack_push(n);
+		$$ = 1;
+	}
+
+	| ident ASSIGN expr {
+		node* n = malloc(sizeof(node));
+		node_init(n, NODE_ASSIGN, "", line);
+
+		node* rhs = stack_pop();
+		node* lhs = stack_pop();
+
+		node_add_child(n, lhs);
+		node_add_child(n, rhs);
+
+		stack_push(n);
+
+		$$ = 1;
+	}
+
+	| LET_MUT ident ASSIGN expr {
+		node* n = malloc(sizeof(node));
+		node_init(n, NODE_VARDECL, "", line);
+
+		node* rhs = stack_pop();
+		node* lhs = stack_pop();
+
+		node_add_child(n, lhs);
+		node_add_child(n, rhs);
+
+		stack_push(n);
+
+		$$ = 1;
+	}
+
+	| LET ident ASSIGN expr {
+		node* n = malloc(sizeof(node));
+		node_init(n, NODE_CONSTDECL, "", line);
+
+		node* rhs = stack_pop();
+		node* lhs = stack_pop();
+
+		node_add_child(n, lhs);
+		node_add_child(n, rhs);
+
+		stack_push(n);
+
+		$$ = 1;
+	}
+
+	| CONTINUE {
+		node* n = malloc(sizeof(node));
+		node_init(n, NODE_CONTINUE, "", line);
+		stack_push(n);
+		$$ = 1;
+	}
+
+	| BREAK {
+		node* n = malloc(sizeof(node));
+		node_init(n, NODE_BREAK, "", line);
+		stack_push(n);
+		$$ = 1;
+	}
+
+
+    	// INDEX
+	| expr array ASSIGN expr {
+		node* n = malloc(sizeof(node));
+		node_init(n, NODE_ASSIGN, "", line);
+
+		node* expr_node = stack_pop();
+		node* array_node = stack_pop();
+		node* ident_node = stack_pop();
+
+		node_add_child(n, ident_node);
+		node_add_child(n, array_node);
+		node_add_child(n, expr_node);
+
+		stack_push(n);
+
+		$$ = 1;
+	}
+
+    	| ASSERT expr {
+		node *n = malloc(sizeof(node));
+		node_init(n, NODE_ASSERT, "", line);
+		node_add_child(n, stack_pop());
+		stack_push(n);
+
+		$$ = 1;
+	}
+;
+
 if_rec:
-	ELSE_COND IF_COND expr block if_rec {
+	ELSE_COND IF_COND expr block_or_expr if_rec {
 		node* n = malloc(sizeof(node));
 		node_init(n, NODE_IF, "", line);
 		
@@ -435,7 +456,7 @@ if_rec:
 		$$ = 1;
 	}
 
-	| ELSE_COND expr END {
+	| ELSE_COND block_or_expr END {
 		node* n = malloc(sizeof(node));
 		node_init(n, NODE_IF, "", line);
 		
@@ -449,8 +470,10 @@ if_rec:
 	}
 ;
 
+block_or_expr: block | expr;
+
 if:
-	IF_COND expr block if_rec {
+	IF_COND expr block_or_expr if_rec {
 		node* n = malloc(sizeof(node));
 		node_init(n, NODE_IF, "", line);
 		
@@ -467,7 +490,7 @@ if:
 		$$ = 1;
 	}
 
-	| IF_COND expr block END {
+	| IF_COND expr block_or_expr END {
 		node* n = malloc(sizeof(node));
 		node_init(n, NODE_IF, "", line);
 		
@@ -502,8 +525,168 @@ expr_unop:
 	}
 ;
 
-type_list: 
+fun_param:
+	ident AS type {
+		node *n = malloc(sizeof(node));
+		node_init(n, NODE_FUN_PARAM, "", line);
+
+		node* type_node = stack_pop();
+		node* ident_node = stack_pop();
+
+		node_add_child(n, ident_node);
+		node_add_child(n, type_node);
+		
+		stack_push(n);
+
+		$$ = 1;
+	}
+
+fun_param:
+	ident AS type
+;
+
+fun_params:
+	{ $$ = 0; }
+	| fun_param {
+		$$ = $1;
+	}
+
+	| fun_params COMMA fun_param {
+		$$ = $1 + $3;
+	}
+;
+
+fun_ret_list:
 	type { $$ = $1; }
+	| fun_ret_list COMMA type {
+		$$ = $1 + $3;
+	}
+;
+
+fun_rets: 
+ 	{
+		node* n = malloc(sizeof(node));
+		node_init(n, NODE_FUN_RET, "", line);
+		stack_push(n);
+
+		$$ = 1;
+	}
+
+	| AS fun_ret_list {
+		node* n = malloc(sizeof(node));
+		node_init(n, NODE_FUN_RET, "", line);
+
+		node* rets[$2];
+
+		for (size_t i=0; i<$2; i++)
+		{
+			rets[$2 - 1 - i] = stack_pop();
+		}
+
+		for (size_t i=0; i<$2; i++)
+		{
+			node_add_child(n, rets[i]);
+		}
+
+		stack_push(n);
+
+		$$ = 1;
+	}
+;
+
+fun:
+   	FUN OPAR fun_params CPAR fun_rets block END {
+		node* n = malloc(sizeof(node));
+		node_init(n, NODE_FUN, "", line);
+		
+		node* block_node = stack_pop();
+		assert(block_node);
+
+		node* ret_node = stack_pop();
+		assert(ret_node);
+	
+		if ($3 > 0)
+		{
+			node* params[$3];
+
+			for (size_t i=0; i<$3; i++)
+			{
+				params[i] = stack_pop();
+			}
+
+			for (size_t i=0; i<$3; i++)
+			{
+				node_add_child(n, params[$3 - 1 - i]);
+			}
+		}
+
+		node_add_child(n, ret_node);
+		node_add_child(n, block_node);
+
+		stack_push(n);
+
+		$$ = 1; 
+	}
+;
+
+fun_args:
+	expr_list {
+		node* n = malloc(sizeof(node));
+		node_init(n, NODE_ARGS, "", line);
+		size_t const SZ = $1;
+
+		node* args[SZ];
+
+		for (size_t i=0; i<SZ; i++)
+		{
+			args[$1 - 1 - i] = stack_pop();
+		}
+
+		for (size_t i=0; i<SZ; i++)
+		{
+			node_add_child(n, args[i]);
+		}
+
+		stack_push(n);
+
+		$$ = 1;
+	}
+;
+
+fun_call:
+	MUL expr {
+		node* n = malloc(sizeof(node));
+		node_init(n, NODE_CALL, "", line);
+		
+		node* args = malloc(sizeof(node));
+		node_init(args, NODE_ARGS, "", line);
+
+		node* fn_expr = stack_pop(); 
+		
+		node_add_child(n, fn_expr);
+		node_add_child(n, args);
+
+		stack_push(n);
+		$$ = 1;
+	}
+
+	| expr fun_args {
+		node* n = malloc(sizeof(node));
+		node_init(n, NODE_CALL, "", line);
+		
+		node* args = stack_pop(); 
+		node* fn_expr = stack_pop(); 
+		
+		node_add_child(n, fn_expr);
+		node_add_child(n, args);
+
+		stack_push(n);
+		$$ = 1;
+	}
+;
+
+type_list: { $$ = 0; } 
+	| type { $$ = $1; }
 	| type_list COMMA type { $$ = $1 + $3; }
 
 ;
@@ -533,10 +716,55 @@ block:
 ;
 
 type: 	
-    	TYPE LT type_list GT {
+    	 FUN LT type_list COLON type_list GT {
+		node* n = malloc(sizeof(node));
+		node_init(n, NODE_FUN_TYPE, "", line);
+
+		node* right = malloc(sizeof(node));
+		node_init(right, NODE_TYPE, "", line);
+		
+		size_t SZ = $5;
+		node* all_right[SZ];
+
+		for (size_t i=0; i<SZ; i++)
+		{
+			all_right[i] = stack_pop();
+		}
+
+		for (size_t i=0; i<SZ; i++)
+		{
+			node_add_child(right, all_right[i]);
+		}
+		
+		node* left = malloc(sizeof(node));
+		node_init(left, NODE_TYPE, "", line);
+
+		SZ = $3;
+		node* all_left[SZ];
+
+		for (size_t i=0; i<SZ; i++)
+		{
+			all_left[i] = stack_pop();
+		}
+
+		for (size_t i=0; i<SZ; i++)
+		{
+			node_add_child(left, all_left[i]);
+		}
+		
+		node_add_child(n, left);
+		node_add_child(n, right);
+
+		stack_push(n);
+
+		$$ = 1;
+	}
+
+    	| TYPE LT type_list GT {
 		node* n = malloc(sizeof(node));
 		node_init(n, NODE_TYPE, $1, line);
 		free($1);
+
 		size_t const SZ = $3;
 		node* all[SZ];
 
@@ -595,6 +823,7 @@ ident: IDENT {
 
 builtins:
 	type {}
+	| fun {}
 
 	| STRING { 
 		node* n = malloc(sizeof(node));
diff --git a/src/program.c b/src/program.c
index 9c9f3a5..18dd7e4 100644
--- a/src/program.c
+++ b/src/program.c
@@ -37,6 +37,27 @@ void program_free(program* self)
 	self->pool.capacity = 0;
 }
 
+program* program_new_clone(program* self)
+{
+	assert(self);
+	program* clone = malloc(sizeof(program));
+	program_init(clone);
+	
+	for (size_t i=0; i < self->instrs.size; i++)
+	{
+		program_add_instr(clone, self->instrs.data[i]->opcode
+					, self->instrs.data[i]->param);
+	}
+	
+	for (size_t i=0; i < self->pool.size; i++)
+	{
+		assert(self->pool.data[i]);
+		program_add_pool(clone, self->pool.data[i]);
+	}
+
+	return clone;
+}
+
 void program_set_instr(program* self, size_t index, int opcode, int param)
 {
 	assert(self);
@@ -99,12 +120,15 @@ size_t program_add_pool(program* self, value* val)
 		self->pool.capacity *= 2;
 		self->pool.data = realloc(
 			self->pool.data,
-			sizeof(value) * self->pool.capacity
+			sizeof(value*) * self->pool.capacity
 		);
 	}
-	size_t idx = self->pool.size;
-	self->pool.data[idx] = value_new_clone(val);
 
+	size_t idx = self->pool.size;
+	value* new_val = value_new_clone(val);
+	assert(new_val);
+	self->pool.data[idx] = new_val;
+	
 	self->pool.size++;
 
 	return idx;
diff --git a/src/program.h b/src/program.h
index c0bdd72..f76be52 100644
--- a/src/program.h
+++ b/src/program.h
@@ -29,6 +29,8 @@ typedef struct {
 void program_init(program* self);
 void program_free(program* self);
 
+program* program_new_clone(program* self);
+
 size_t program_add_instr(program* self, int opcode, int param);
 void program_set_instr(program* self, size_t index, int opcode, int param);
 void program_set_param(program* self, size_t index, int param);
diff --git a/src/symtable.c b/src/symtable.c
index bfc2776..9fc8adc 100644
--- a/src/symtable.c
+++ b/src/symtable.c
@@ -42,6 +42,36 @@ void symentry_free(symentry* self)
 	free(self->ty);
 }
 
+symtable* symtable_new_clone(symtable* self)
+{
+	symtable* clone = malloc(sizeof(symtable));
+	symtable_init(clone);
+	
+	clone->entries.capacity = self->entries.capacity;
+	clone->entries.data = realloc(clone->entries.data, 
+			sizeof(symentry*) * clone->entries.capacity);
+
+	for (size_t i=0; i<self->entries.size; i++)
+	{
+		symentry* entry = self->entries.data[i];
+		symentry* clone_entry = malloc(sizeof(symentry));
+
+		clone_entry->id = entry->id;
+		clone_entry->name = str_new(entry->name);
+		clone_entry->is_mut = entry->is_mut;
+		clone_entry->scope = entry->scope;
+		clone_entry->ty = type_new_clone(entry->ty);
+		clone_entry->sym_node = node_new_clone(entry->sym_node);
+		clone->entries.data[i] = clone_entry;
+	}
+	
+	clone->entries.size = self->entries.size;
+	clone->id = self->id;
+	clone->scope = self->scope;
+
+	return clone;
+}
+
 size_t symtable_declare_mut(symtable* self, char const* name, type* ty, node* sym_node)
 {
 	assert(self);
diff --git a/src/symtable.h b/src/symtable.h
index 8f13d37..600ea38 100644
--- a/src/symtable.h
+++ b/src/symtable.h
@@ -29,6 +29,7 @@ void symtable_init(symtable* self);
 void symtable_free(symtable* self);
 void symentry_free(symentry* self);
 
+symtable* symtable_new_clone(symtable* self);
 size_t symtable_declare(symtable* self, char const* name, type* ty, node* sym_node);
 size_t symtable_declare_mut(symtable* self, char const* name, type* ty, node* sym_node);
 symentry* symtable_find(symtable* self, char const* name);
diff --git a/src/type.c b/src/type.c
index 7e47884..e1aff9c 100644
--- a/src/type.c
+++ b/src/type.c
@@ -12,6 +12,103 @@ void type_init(type* self, int base_type)
 	self->sub_types.data = malloc(sizeof(type*));
 }
 
+type* type_init_from_node(node* root)
+{
+	assert(root);
+	type* ty = malloc(sizeof(type));
+	
+	if (root->type == NODE_FUN_TYPE)
+	{
+		type_init(ty, TY_FUNCTION);
+
+		node* params = root->children.data[0];
+
+		for (size_t i=0; i< params->children.size; i++)
+		{
+			type* t = type_new_from_node(params->children.data[i]);
+			type_add_sub_type(ty, t);
+			type_free(t); free(t);
+		}
+		
+		node* rets = root->children.data[1];
+
+		for (size_t i=0; i< rets->children.size; i++)
+		{
+			type* t = type_new_from_node(rets->children.data[i]);
+			type_add_sub_type(ty, t);
+			type_free(t); free(t);
+		}
+
+		return ty;
+	}
+
+	else if (strcmp(root->value, "fun") == 0)
+	{
+		type_init(ty, TY_FUNCTION);
+	}
+
+	else if (strcmp(root->value, "int") == 0)
+	{
+		type_init(ty, TY_INTEGER);
+	}
+
+	else if (strcmp(root->value, "float") == 0)
+	{
+		type_init(ty, TY_FLOAT);
+	}
+
+	else if (strcmp(root->value, "str") == 0)
+	{
+		type_init(ty, TY_STRING);
+	}
+
+	else if (strcmp(root->value, "bool") == 0)
+	{
+		type_init(ty, TY_BOOLEAN);
+	}
+
+	else if (strcmp(root->value, "type") == 0)
+	{
+		type_init(ty, TY_TYPE);
+	}
+
+	else if (strcmp(root->value, "array") == 0)
+	{
+		type_init(ty, TY_ARRAY);
+		ty->kind = KIND_SEQUENTIAL;
+	}
+	else if (root->type == NODE_ADD)
+	{
+		type_init(ty, TY_TYPE);
+		ty->kind = KIND_DISJUNCTION;
+	}
+	else if (root->type == NODE_MUL)
+	{
+		type_init(ty, TY_TYPE);
+		ty->kind = KIND_CONJUNCTION;
+	}
+	else
+	{
+		char c[512];
+		node_str(root, c, 512);
+		printf("errnode = %s\n", c);
+		fprintf(stderr, 
+			"E(%d): cannot compile unknown type '%s').\n",
+			root->lineno,
+			NodeTypeStr[root->type]);
+	}
+
+	for (size_t i=0; i<root->children.size; i++)
+	{
+		type* sub = type_new_from_node(root->children.data[i]);
+		type_add_sub_type(ty, sub);
+		type_free(sub);
+		free(sub);
+	}
+
+	return ty;
+}
+
 void type_init_array(type* self, type* array_type)
 {
 	assert(self);
@@ -35,7 +132,12 @@ void type_free(type* self)
 	self->sub_types.size = 0;
 	self->sub_types.capacity = 0;
 	self->sub_types.data = NULL;
+}
 
+type* type_new_from_node(node* root)
+{
+	assert(root);
+	return type_init_from_node(root);
 }
 
 void type_add_sub_type(type* self, type* rhs)
@@ -92,7 +194,8 @@ int type_equals(type* self, type* rhs)
 		return 0;
 	}
 	
-	if (self->kind != KIND_SEQUENTIAL)
+	if (self->kind == KIND_CONJUNCTION
+		|| self->kind == KIND_DISJUNCTION)
 	{
 		for (int i=0; i<TY_TYPE_COUNT; i++)
 		{
@@ -138,10 +241,16 @@ size_t type_str(type* self, char* buffer, size_t size)
 			sz += snprintf(buffer + sz, size - sz, "<");
 		}
 	}
-
+	
 	for (size_t i=0; i<self->sub_types.size; i++)
 	{
-		if (i > 0)
+		
+		if ((i == 0 || self->sub_types.data[i - 1 ]->kind != KIND_RETURN)
+		 	&& self->sub_types.data[i]->kind == KIND_RETURN)
+		{
+			sz += snprintf(buffer + sz, size - sz, " : ");
+		}
+		else if (i > 0)
 		{
 			sz += snprintf(buffer + sz, size - sz, ", ");
 		}
diff --git a/src/type.h b/src/type.h
index 559f389..06215d6 100644
--- a/src/type.h
+++ b/src/type.h
@@ -2,6 +2,7 @@
 #define TYPE_H
 
 #include "commons.h"
+#include "node.h"
 
 #define TYPES(G) \
 	G(TY_NIL), \
@@ -11,6 +12,7 @@
 	G(TY_STRING), \
 	G(TY_ARRAY), \
 	G(TY_TYPE), \
+	G(TY_FUNCTION), \
 	G(TY_TYPE_COUNT)
 
 enum Types {
@@ -22,7 +24,8 @@ extern char const* TypesStr[];
 enum TypeKind {
 	KIND_DISJUNCTION,
 	KIND_CONJUNCTION,
-	KIND_SEQUENTIAL
+	KIND_SEQUENTIAL,
+	KIND_RETURN
 };
 
 typedef struct type {
@@ -37,9 +40,11 @@ typedef struct type {
 } type;
 
 void type_init(type* self, int base_type);
+type* type_init_from_node(node* root);
 void type_init_array(type* self, type* array_type);
 void type_free(type* self);
 
+type* type_new_from_node(node* root);
 void type_add_sub_type(type* self, type* rhs);
 
 type* type_new_clone(type* self);
diff --git a/src/value.c b/src/value.c
index bbd42c7..7eaa4a9 100644
--- a/src/value.c
+++ b/src/value.c
@@ -67,6 +67,17 @@ void value_init_type(value* self, type* ty, int lineno)
 	type_init(self->type, TY_TYPE);
 }
 
+void value_init_fun(value* self, fun* f, int lineno)
+{
+	assert(self);
+	assert(f);
+	
+	self->val.fun_val = fun_new_clone(f);
+
+	self->lineno = lineno;
+	self->type = type_new_clone(f->ty);
+}
+
 void value_free(value* self)
 {
 	assert(self);
@@ -94,6 +105,14 @@ void value_free(value* self)
 		self->val.array_val = NULL;
 	}
 
+	if (self->type->base_type == TY_FUNCTION
+		&& self->val.fun_val != NULL)
+	{
+		fun_free(self->val.fun_val);
+		free(self->val.fun_val);
+		self->val.fun_val = NULL;
+	}
+
 	type_free(self->type);
 	free(self->type);
 	self->type = NULL;
@@ -121,6 +140,11 @@ value* value_new_clone(value* self)
 		clone->val.array_val = array_new_clone(self->val.array_val);
 	}
 
+	if (self->type->base_type == TY_FUNCTION)
+	{
+		clone->val.fun_val = fun_new_clone(self->val.fun_val);
+	}
+
 	clone->lineno = self->lineno;
 
 	return clone;
@@ -167,6 +191,11 @@ int value_equals(value* self, value* rhs)
 		return array_equals(self->val.array_val, rhs->val.array_val);
 	}
 
+	if (self->type->base_type == TY_FUNCTION)
+	{
+		return fun_equals(self->val.fun_val, rhs->val.fun_val);
+	}
+
 	size_t const SZ = 512;
 	char ty_str[SZ];
 	
@@ -190,6 +219,12 @@ size_t value_str(value* self, char* buffer, size_t size)
 		case TY_ARRAY:
 			return array_str(self->val.array_val, buffer, size);
 
+		case TY_FUNCTION:
+			return fun_str(self->val.fun_val, buffer, size);
+
+		case TY_FLOAT:
+			return snprintf(buffer, size, "%f", 
+					self->val.real_float);
 		case TY_STRING:
 			return snprintf(buffer, size, "%s", 
 					self->val.string);
diff --git a/src/value.h b/src/value.h
index 901c2dd..37d151f 100644
--- a/src/value.h
+++ b/src/value.h
@@ -4,6 +4,7 @@
 #include "commons.h"
 #include "type.h"
 #include "array.h"
+#include "fun.h"
 
 typedef struct {
 	type* type;
@@ -15,6 +16,8 @@ typedef struct {
 		char* string;
 		array* array_val;
 		type* type_val;
+		fun* fun_val;
+
 	} val;
 } value;
 
@@ -24,6 +27,7 @@ void value_init_float(value* self, float real_float, int lineno);
 void value_init_string(value* self, char* string, int lineno);
 void value_init_array(value* self, array* arr, int lineno);
 void value_init_type(value* self, type* ty, int lineno);
+void value_init_fun(value* self, fun* f, int lineno);
 
 void value_free(value* self);
 
diff --git a/src/vm.c b/src/vm.c
index 924be02..2de56e9 100644
--- a/src/vm.c
+++ b/src/vm.c
@@ -109,6 +109,9 @@ void vm_exec(vm* self, program* prog)
 
 			case OP_TEQ: vm_teq(self); break;
 
+			case OP_CALL: vm_call(self, param); break;
+			case OP_RET: vm_ret(self); break;
+
 			default: {
 				fprintf(stderr, "unknown opcode %s\n",
 						OpcodesStr[opcode]);
@@ -1142,3 +1145,51 @@ void vm_br(vm* self, int param)
 	assert(self);
 	self->pc = param;
 }
+
+void vm_call(vm* self, int param)
+{
+	assert(self);
+	
+	// get function and parameters
+	value* args[param];
+
+	for (int i=0; i<param; i++)
+	{
+		args[param - 1 - i] = vm_pop_value(self);
+	}
+
+	value* fun_val = vm_pop_value(self);
+	fun* f = fun_val->val.fun_val;
+	
+	// create new ecxecution environment
+	vm v;
+	vm_init(&v);
+
+	for (int i=0; i<param; i++)
+	{
+		vm_set(&v, i, args[i]);	
+	}
+
+	// execute function
+	vm_exec(&v, (program*) f->prog);
+	
+	value* ret = value_new_clone(v.stack.data[v.stack.size - 1]);
+	vm_push_value(self, ret);
+
+	vm_free(&v);
+	
+	for (int i=0; i<param; i++)
+	{
+		value_free(args[i]); free(args[i]);
+	}
+
+	value_free(fun_val); free(fun_val);
+	
+	self->pc++;
+}
+
+void vm_ret(vm* self)
+{
+	assert(self);
+	self->pc = self->prog->instrs.size;
+}
diff --git a/src/vm.h b/src/vm.h
index 2457c55..41a2a77 100644
--- a/src/vm.h
+++ b/src/vm.h
@@ -95,4 +95,7 @@ void vm_teq(vm* self);
 void vm_brf(vm* self, int param);
 void vm_br(vm* self, int param);
 
+void vm_call(vm* self, int param);
+void vm_ret(vm* self);
+
 #endif
diff --git a/tests/err_fun.wuz b/tests/err_fun.wuz
new file mode 100644
index 0000000..a5e734a
--- /dev/null
+++ b/tests/err_fun.wuz
@@ -0,0 +1 @@
+let f = fun () as int return 1.2; end ; f
diff --git a/tests/err_vars.wuz b/tests/err_vars.wuz
index 7d264f7..8c5f763 100644
--- a/tests/err_vars.wuz
+++ b/tests/err_vars.wuz
@@ -1,8 +1,8 @@
-let x = 0 x + 1.2
-let x = false x + "false"
-let x=0 let x=7
-let x=[1, 2] x[7, 9]
-let x = 0 x = 3.2
-let x = 0 x = 7
-let x=[1, 2] x[0] = 3.2
-let x=[3, 4] x[0] = 7
+let x = 0 ; x + 1.2
+let x = false ; x + "false"
+let x=0 ; let x=7
+let x=[1, 2] ; x[7, 9]
+let x = 0 ; x = 3.2
+let x = 0 ; x = 7
+let x=[1, 2] ; x[0] = 3.2
+let x=[3, 4] ; x[0] = 7
diff --git a/tests/errors.sh b/tests/errors.sh
index d3fb647..a49d7bd 100755
--- a/tests/errors.sh
+++ b/tests/errors.sh
@@ -9,7 +9,6 @@ echo -e "\e[34m=== Error Testing ===\e[0m"
 for file in $(find . -name "err_*.wuz") 
 do
 	LINE=1
-	
 	while read line; 
 	do
 		echo "$line" | wuz &> /dev/null
diff --git a/tests/test_fun.wuz b/tests/test_fun.wuz
new file mode 100644
index 0000000..4915403
--- /dev/null
+++ b/tests/test_fun.wuz
@@ -0,0 +1,32 @@
+assert fun<int:int> is type
+assert fun<int:> is type
+assert fun<:int> is type
+assert fun<int, int: float, str> is type
+assert fun< fun<:> : int> is type
+
+let a = fun (x as int, y as int) as int 
+	0
+end
+
+assert a is fun<int, int: int>
+assert !(a is fun<:>)
+
+let b = fun (x as int) as int
+	return x * 7
+end
+
+assert 42 == b 6
+
+let c = fun () as int
+	return 3 * 6
+end
+
+assert 18 == *c
+
+let d = fun () as int 
+	return 43
+	27
+end
+
+assert 43 == *d
+
diff --git a/tests/test_integers.wuz b/tests/test_integers.wuz
index 25af4c3..f1097b5 100644
--- a/tests/test_integers.wuz
+++ b/tests/test_integers.wuz
@@ -20,3 +20,4 @@ assert 64 == 2^(3+3)
 assert 1 == -2 - -3
 
 assert 5 + 7 == 12
+